hmm, not a lot of help.
anyway, I THOUGHT I had done a search of launch 4j error (which returned nothing) but I must have had a typo, as I just did another search which turned up (quite a few) threads with people having exactly the same problems as I did.
I am very uneducated with computers, so some of the solutions seemed very daunting to say the least, but a few common themes turned up, one which I suspected might have applied to me being that of some sort of problem due to bluetooth (I noticed all these bluetooth ports in the set up phase).
Being as dumb as I am with computers, about the easiest and only thing I could do was delete bluetooth and see what happened , ie throw the coin and pray.
Long story short, as soon as I removed bluetooth the program up and loaded and everything is working fine.
Personally I have no need for bluetooth on my computer...not even really sure what it is anyway!! haha, so it is no skin off my nose to delete it.
I cannot help you if you have my problem yet need bluetooth!
Thanks to all who looked (at least), I am mainly posting this for the possible benefit of future readers.
I WOULD l;ike to make the following observation if I may, hope I do not offend too many. It did seem a relatively common problem, quite a few threads on it (and mostly recent too, does that coincide with a new release of something??), yet in the majority of cases those posters asking for help did not get an awful lot.
that could indicate that a search should fix most of the cases (as I said, I did search but missed it first time around) yet given the title of this subforum, I wonder if there should be sticky threads for the common problems that come up? An obvious title choice for a thread dealing with this subject would be 'launch 4j error', I and many others would find these sticky threads very easily.
Anyway, luckily for me it was an easy fix, hope it helps others. there are other fixes in the threads on this subject, so have a look at them if bluetooth does not apply to you.
and maybe one day all the solutions might appear in the one sticky thread (and for all the other common problems)